Slopes in phylite, of civil works or of mining, are conspicuous in the region of the Quadrilátero Ferrífero, MG. In the great majority it verifies the occurrence of instabilization mechanisms, such as flexural toppling, not usual in slopes of other rocky materials. We used the computational method of finite differences implemented in the software FLAC who allows the consideration of great deformations of the analyzed massif (what it can occur in a slope of phylite/schist), and it is especially apt to model the dynamic process of instabilization of a slope. They were accomplished 255 parametric analyses, corresponding to a combination of slopes geometries with angles varying from 30º to 60º and heights from 50 to 200m, of angles of the foliation varying from 40º to 80º, and of four different geomechanical classes of massifs. The results allowed the creation of three stability charts for the geomechanical classes II, III and IV, with curves that define stable and unstable zones of flexural toppling, for different heights of slope. Such charts are adequate for preliminary analyses of slopes designing, in phylites and schists of the Quadrilátero Ferrífero. The computational analyses allowed, yet, a better comprehension of the mechanics of the instabilization process of such slopes.
flexural toppling; slopes in phylite; computational modeling; FLAC
